I had recently purchased spacers from H&R (15mm), but i couldn't take the vibrations anymore, so opted to switch back to my stock setup! the problem is that I didnt feel like changing the studs back to the stock ones - Now if I put my wheels back on and use the stock lug nuts, will it be safe? or are they not long enough to hold for that long? I drove a couple minutes with them, and it feels fine, But i was wondering if anyone knew the safety of this??

THANX for you time